Submersible sump pump control



Jan. 13, 1953 E. .1. scHAEFl-:R

SUBMERSIBLE SUMP PUMP CONTROL Filed Feb. 17, 1951 pill I Hb N JSC/zaaef;

M, ,7mzk 1 y@ Patented Jan. 13, 1953 UNITED STATES ATENT OFFICE SUBMERSIBLE SUMP PUMP CONTROL Edward J. Schaefer, Fort Wayne, Ind.

Application February 17, 1951, Serial No. 211,544

(Cl. IGS-26) 9 Claims. 1

This invention relates generally to sump pumps and more particularly to a novel control means for a sump pump of the submersible type.

In my copending application S. N. 177,674, filed August 4, 1950, I have described and claimed a sump pump arrangement wherein the electric motor for the pump unit is of the submersible type and is positioned immediately adjacent the pump unit. The motor is rendered submersible by means of a generally cylindrical shell or enclosure which includes a flexible diaphragm means adapted to actuate a control switch for the motor in response to changes of water level outside the enclosure. Preferably, the diaphragm means constitutes an end portion of the motor enclosure and, in addition, the diaphragm means is preferably arranged so that the entire motor enclosure functions as a float control.

With the sump pump arrangement comprising my earlier invention the pump is automatically turned on when the Water in the sump reaches a predetermined maximum level sufficient to deect the diaphragm means and actuate the control switch. The pump continues to operate until the Water in the sump recedes to a minimum level such that the head of water in the sump is insuilicient to deect the diaphragm means whereupon the control switch returns to its normal oil position. Thus, it will be seen that the device functions to maintain the water in the sump at a certain minimum level but in no case is the sump actually pumped to substantial emptiness.

The present invention relates to a control means adapted to be used in combination with a sump pump arrangement of the type disclosed in my earlier copending application for the purpose of insuring continued operation of the pump until the sump is substantially dry.

Accordingly, a primary object of my invention is to provide a novel sump pump arrangement adapted to empty a sump or the like to substantial dryness.

A further object of the invention is to provide novel control means for a sump pump which insures continued operation of the pump until it begins to draw air.

Another object of the invention is to provide a Ynovel submersible sump pump arrangement having a motor enclosure including main control means for the motor and an auxiliary control device adapted to cooperate with the main control means for insuring operation of the pump until it ceases to discharge liquid.

Other objects and advantages of the invention will become evident from the subsequent detailed description taken in conjunction with the accompanying drawing wherein:

Fig. 1 is a vertical sectional view of a sump pump arrangement comprising one specific embodiment of my invention; and

Fig. 2 is a view similar to Fig. l but showing a modied form of the invention.

Referring iirst to Fig. 1 of the drawing, wherein one specific embodiment of my invention is shown merely by way of illustration, the device comprises an electric motor 6 of a conventional type having a rotor shaft 'I depending therefrom. Disposed below the motor 6 and immediately adjacent thereto is a centrifugal pump unit 8 of a conventional type having an inlet 9 and an outlet I I and arranged so that the pump casing supports the weight of the motor. The pump impeller, indicated at I2, is secured at the lower end of the shaft 'I and the latter is provided with a suitable rotating seal I3 to prevent entry of water to the motor through the shaft outlet.

Surrounding the motor 6 for rendering the latter submersible is an enclosure, indicated generally at I4, which comprises a cylindrical body portion I6 supported on the motor B by means of a pair of substantially identical upper and lower end portions designated generally by the ref erence numeral Il. The body portion Ic is preferably formed from relatively thin corrosionresistant metal such as stainless steel.

Each of the end portions I'I of the enclosure I4 comprises a deflectable diaphragm means including a relatively thin annular element I8 which may be of metal. The outer marginal or peripheral edge of each of the elements I8 is turned inwardly toward the motor B to provide a flange or rim IB which is rigidly secured and sealed, preferably by welding, to the inner periphery of the body portion I6 of the enclosure I4. The inner marginal or peripheral edge of each element I8 is turned outwardly away from the motor 6, as at 2 I, and is flexibly attached to the motor 6 by means of an annular connecting collar, indicated generally at 22. The collars 22 are preferably formed from a resilient material such as rubber or the like and are generally U-shaped in cross-section. Thus, each of the collars 22 is formed with relatively heavy concentric inner and outer ring portions 23 and 2li, respectively, which are interconnected adjacent their outermost edges by a relatively thin integral connecting portion 26. The collars 22 are secured to the elements I8 by means of the outwardly turned edges 2l of the latter which are flared outwardly to a slight extent in order to aaaiov 3 provide a snug engagement with the inner periphery of the collar portions 24. The inner portions 23 of the collars 22 t snugly around the upper and lower hub portions of the motor 6, as indicated at 21 and 28, respectively.

Thus, the combination of the enclosure I4 with the upper and lower end portions or diaphragm means II forms a watertight casing which renders the motor S submersible and at the same time constitutes a ioat which is free for limited movement in a vertical direction upon flexing of the connecting portions 26 of the collars 22, as hereinafter described. l

For automatically regulating the operation of he motor 25, a control switch 29- having a depressiole spring-pressed operating member or button 3i is mounted adjacent the upper portion or the motor with the operating button 3| facina the upper annular element I8 in operative relation therewith. The switch 29 is of a type in which only a relatively slight movement of the operating button 3i, e. g. als ofy an inch, is sufficient to cause the actuationY of the switch between on and ofi positions. It will be unrstood that the enclosure i4, which is sealed o the upper and lower ends' of the motor S .by

ie end diaphragm means Ii, will function as a. noa-t when the mot-or and pump unit are disposed. at the bottom of a sump. Thus, as the water level in the sumpV rises, the enclosure I4 containing trapped air is lifted upwardly relative to the motor by the buoyant effect of the water, the flexible connecting portions 25 Aof the col-lars 22 permitting. this upward movement. Upon upward movement of the enclosure I4, the upper element I 8 `moves away from the operating button 3i permitting the latter to move outwardly whereby to complet Vtnefelectrical circuit for the motor 6 andv thereby start the pump in operation. Similarly, as-the water level in the sump recedes during operation of the pump 8,.the weight ofthe enclosure I4 causes the'latter to move downwardly whereuponA the upper element engages theswitchbutton 3i anddepresses the latter to shut olif the motor.

Means comprising a bridge member and guide screws (not shownin detail in thev drawing) is provided at the upper er1-dor the motor-for guiding and limiting the'verticalmovementof the float enclosure I4 relative to the motor 6.-V Details of thisV structure are. described fully in my copen'dingv application S'. N; 177,674 and needA not be repeated here. A dome-*shaped cover 32 is detachably mounted. over the upper end of the device with the depending skirt portion thereof fitting over and frictionally engaging the upper'end of, the body I6 of the enclosure ld, as at 33. A handle 3d is fastened to the cover 32 for raising., and lowering the entire unit, Means (not shown). comprising suitable electric wires isV also provided for conductingl electric current to the switch 2S and the motor 6.

ns the motor heats up during. operation, the temperature vof the airtrapped inside of the enclosure I4 may vary as muchas 50 C- Under such circumstances it is desirable to compensate for varying air pressure in order to avoid the possibility that an increase in pressure inside the enclosure might cause movement of the enclosure relative to the motor and thereby eect-the operation ot the device independently of any change of water level. However, the provision of substantially identical diaphragm means Il,

i. e. diaphragm means having substantially the saine exposed areas, at the top and bottom of the 4 cylindrical portion I6 of the enclosure I4 balances out the eiTect of varying air pressure within the enclosure and leaves the upward and downward movement of the enclosure I4 dependent solely upon external pressure. In other words, even if the pressure of the air surrounding the motor 6 and within the enclosure I4 should increase, the net force tending to move the enclosure'4 I4 relative to the motor S' will be zero because the force acting against the upper diaphragm means I'I tending to move the enclosure I4 upwardly will be counteracted by a substantiallyidentical force acting against the lower diaphragm meansy II tending to move the enclosurev Idownwardly. The cover 32 is provided with suitable ,means ,(not shown) for permitting drainage of water from the space between the cover 32 and the upper diaphragm means i? and also for preventing airl from being trapped in this space..

From the foregoing. dscripti`on it will be seen that the main control means -forthesump pump unit comprises the-,diaphragm means Ii which are deflectable in response to changes in liquid levelioutside the enclosure Idffor actuating ,the control switch 27'9.- With this main control means alone,` as. in the invention described in my earlier copending application, the.- pump shuts oil' at aA predetermined minimum .water level in the sump which corresponds. to the level at which the 'buoyant .or liftingeiect .isv lost. Such operation is satisfactory in. manycases, but in other situe ations it may be desirable to have the sump emptied to substantial dryness. The primar-y feature of thev present invention-involves an auxiliary control means which supplements and'V cooper'- ates with themain control .means to insure .continued. operationV of. thepumpuntil the sump is substantially, empty, as hereinafter described in detail'.

Broadly speaking, they auxiliary control means which constiutes the principal featureof my insA vention comprises pressure-transmitting means connected totheA dischargesi'de of the pump ,unit for permitting the. pressure ,ofthe dischargeli'quidY from the pump tooperate the mainpump control.Y In .this ywaythe control switch is'- actu.-

ated independently-of thevliqui'd level outside the motor enclosure. whereby the pump is .keptiin operation-.until it .begins to draw. air at which point the. discharge. pressure, ofcourse, fall's to zero.l

In the embodiment of. the ,invention showny in Fig. lof thedrawing, theauxiliary control means comprises a' conduit. or pipe` 35 .which is threaded at one end. into the. pumpcasin'g. on the dis: charge side offthepumn. e.- g., adjacent the pump outlet` II- as shown in thedrawing. The cone duit 36 terminates in. annpen end which' is disposed below the lower diaphragmv means` I'I'l of the motor enclosure and in slightlyl spaced-1relation therefrom. Thus,. it will be seen that' when. the. pump unit 8jis inoperation ai stream ci -di'schargeli'quid underthe discharge ,pressure of the pump will'be directed upvfardlyinthe manner of a waterjet against the. lowerlside' of the lower diaphragm means' I,

When, the. Waterlevel in the sumpisl relatively high such astocause the il'oat enclosure I4' to be lifted upwardly, thereby actuating, the switch 29; the .ietV of;water issuing from' the conduitv 3S will have no particular el''ect on .theioperat'ion of. the unit. since the eiectof the .high water levelis suflcient to keep the pumpiin operation. However. as the waterl'evel in the' sump recedes the tendency is for the float enclosure I4 to move downwardly, as described above, with the result that the switch 29 would eventually be shut off if there were no other force acting on the float I4. However, the force of the jet of water issuing from the conduit 36 urges the float I4 upwardly with sufcient force to insure continued operation of the pump unit 8 until the water is completely exhausted from the vicinity of the pump inlet 9. Obviously, when the pump begins to draw air through the inlet 9, there will be no liquid pressure issuing from the conduit 36 to act on the float I4 and the float will then move downwardly to shut off the motor.

Fig. 2 of the drawing illustrates a different embodiment of the auxiliary control means, the structure of the unit being otherwise the same as in Fig. 1. The same reference numerals are employed in Fig. 1 and Fig. 2 to illustrate the various parts of the motor. pump unit, and float enclosure. In this form of the invention, the auxiliary control device comprises a conduit 31 threaded at one end into the pump casing adjacent the discharge outlet as in Fig. l. However, instead of the outer end of the conduit being open to direct a jet of water therefrom, the outer end of the conduit 31 is fitted with an expansible bellows 38. The bellows 38 is made of a resilient material such as rubber and the outer closed end thereof is positioned in fiatwise contact with the lower diaphragm means I1 of the fioat enclosure I4. It will be understood that when the pump unit 8 is in operation and liquid is being discharged from the outlet II, the pressure of the discharge liquid in the conduit 31 will cause the r bellows 38 to expand thereby exerting a lifting or upwardly directed force on the bottom of the float I4. As described above in connection with Fig. l, the lifting effect of the bellows 38 insures that the float I4 will be retained in its upper position for continued operation of the pump unit 8 even when the water level in the sump outside the float has diminished to the point where the buoyant effect of the water would no longer lift the float upwardly. Thus, operation of the pump continues until the sump is substantially dry and the pump begins to draw air at which point the bellows 38 will collapse and the float I4 will automatically return to its lower position thereby stopping the operation of the pump.

As a result of the combination of the main control means comprising the deflectable diaphragm and the auxiliary control means constituting the principal feature of the present invention, I am able to control the operation of the pump to insure that the sump is pumped to substantial dryness. The main control means functions primarily to reduce the water level in the sump to a certain minimum point and thereafter the float enclosure surrounding the pump motor is actuated by the auxiliary control means in response to the pressure of the discharge liquid from the pump. Consequently, it may be said that the main control means functions in response to changes in liquid level in the sump, whereas the auxiliary control means functions independently of the liquid level in the sump. Thus, the auxiliary control means constitutes an important adjunct Ito a submersible sump pump of the type described in the present application and in my earlier copending application. This feature is of particular importance in a situation wherein it is desirable to maintain a sump in a substantially dry condition rather than merely maintain- CII mum.

Although the invention has been described in connection withc'ertain specific structural embodiments, it will be understood that various modifications and equivalent structures may be resorted to without departing from the scope of' the invention as defined in the appended claims.

I claim:

1. In a motor driven sump pump, a pump unit, an electric motor connected to said pump unit, a casing structure around said motor to render the same submersible. a control switch for said motor within said casing structure, said casing structure including diaphragm means disposed in operative relation with said switch and deflectable in response to changes in liquid level outside said casing structure for actuating said switch, and means responsive to the liquid pressure at the discharge side of said pump unit for maintaining said diaphragm means in switch-actuating position as long as liquid is being discharged from said pump unit.

2. In a motor driven sump pump, a pump unit, an electric motor connected to said pump unit, a casing structure around said motor to render the same submersible, a control switch for said motor within said casing structure, said casing structure including diaphragm means disposed in operative relation with said switch and deflectable in response to changes in liquid level outside said casing structure for actuating said switch, and means functioning independently of said liquid level for defiecting said diaphragm means in response to the discharge pressure of said pump unit whereby to insure operation of said pump unit until the latter `ceases to discharge liquid.

3. In a motor driven sump pump, a pump unit having an inlet and an outlet, an electric motor connected to i said pump, a casing structure around said motor to render the same submersible, a control switch for said motor within said casing structure, said casing structure including diaphragm means disposed in operative relation with said switch and deilectable in response to changes in liquid level outside said casing structure for actuating said switch, and means communicating between said outlet and said casing structure for effecting deflection of said diaphragm means by the pressure of the discharge liquid from the pump whereby to insure operation of the pump until said inlet begins to draw air.

4. In a motor driven sump pump, a pump unit, an electric motor connected to said pump unit, a control switch for said motor, casing structure around said motor to render the same submersible, main control means for said pump unit comprising a flexible diaphragm constituting an end portion for said casing structure and deflectable in response to changes in liquid level outside said casing structure for actuating said switch, and auxiliary control means comprising a conduit communicating at one end with said pump unit at the discharge side of the latter and having its opposite end disposed adjacent said casing structure for effecting deflection of said diaphragm in response to the pressure of the discharge liquid from the pump unit whereby to insure operation of the pump unit until the latter ceases to discharge liquid.

5. In a motor driven sump pump, a pump unit, an electric motor, a. hollow float chamber sur- 

